FLATHEAD LAKE — Babbling springs and mountain snowmelt aren’t the only water sources feeding Montana’s largest lake.
Others lurk along the shoreline, and they’re unlikely to see mention in tourism campaigns. Many lakeshore homes pump their sewage into underground septic systems, but during a 2014-2015 study, scientists at the Flathead Lake Biological Station found that it wasn’t staying there.
Sampling lakewater near Dayton on Flathead Lake’s west side, they found high levels of E. coli bacteria, a marker for animal waste. “We actually sent [the samples] to an outside lab to do DNA testing,” said Tom Bansak, the Biological Station’s assistant director. "In one particular area, we found that it was human gut fauna entering the surface water and entering the lake.
“So in that case, it was the human DNA that was the smoking gun to validate … our concerns that human waste and failing septic systems were resulting in wastewater reaching Flathead Lake.”
Northwest Montana’s lakes are ringed with houses that have their own underground septic systems, and scientists say many aren’t doing their job well enough, leading to off-putting seepages like Dayton’s. But getting homeowners to adopt better alternatives has proven difficult, and state lawmakers will soon consider a proposal to study why.
For decades, Montanans beyond the reach of sewer lines have installed septic systems to process their toilet flushes and dishwater on-site. Wastewater flows into an underground tank, where its solids sink to the bottom. A pitchfork-shaped array of buried pipes spreads the liquids over a drainage field, where soil either absorbs the wastes or breaks them down.
But age, lack of maintenance and poor soil conditions can keep these systems from working properly, and instead release the liquid, known as “septic leachate.” Two main developments tell scientists that it’s reached surface water.
“Wastewater from septic systems is enriched in nutrients,” Bansak said, “… so looking for high levels of nutrients, especially phosphorus, is an indicator of septic leachate entering the lake and potentially compromising the water quality and water clarity.
“But then there’s also biological contaminants coming out of septic systems, and those would be E. Coli, fecal coliform, basically the bacteria that live in the human digestive tract.”
The Biological Station hasn’t determined the current extent of leachate pollution around Flathead Lake. But research is only part of the challenge, Bansak explained
Pollution can come from either an easy-to-identify “point source,” such as a drainpipe or chimney, or more diffuse “non-point sources.”
The area’s leaky septic systems fall into the latter category, Bansak explained. “Non-point source pollutants are things that are dispersed across the landscape, and they're much harder to regulate and they're much harder to address, because there's lots of little things in a lot of little places.”
The quirks of Northwest Montana’s geography compound the challenge, said Mike Koopal, executive director of the Whitefish Lake Institute. “Every lake’s going to be a little different in terms of...the complexities of the issue, so for one lake it might be distance from infrastructure, for another lake it could be geologic type, for another lake it might be financial related.”
Whitefish Lake’s neighbors have already learned that a range of factors can keep leaky septic pipes in the ground.
In 2012, a Whitefish Lake Institute study confirmed septic leachate’s presence in the water.
A few years later, a preliminary engineering report recommended that the Lion Mountain neighborhood, with 120 lots on the lake’s west shore, connect to the City of Whitefish’s sewer lines, thereby eliminating their need for individual septic systems.
But “the complexity of really comprehending and embracing the concept of non-point source pollution led to us not moving forward on it,” explained Ed Lieser, a member of the board of directors of the Lion Mountain Owners Association and a former Montana state representative.
The project’s costs made it an especially tough sell. “People would be looking at something like an additional 150 bucks a month,” he recalled. “We’ve got a number of people on fixed incomes, and that’s a tough bill to swallow.”
In addition, “if the subdivision chooses to accept city services, then we would be at some point required to be annexed into the city, and when the subdivision is annexed into the city then we would have to start paying city property taxes.” For some of his neighbors, worries about annexation “seem to be overriding concerns about water quality in Whitefish Lake."
Lieser said that the City of Whitefish is still working on possible compromises. But he’s also eyeing a different path to protecting the region’s crystalline waters.
At last month’s Flathead Basin Commission meeting, Lieser, Koopal and the Department of Natural Resources and Conservation’s Mark Bostrom presented a bill for consideration by the state Legislature.
It would task the state’s Legislative Services Division with studying “the barriers (physical, financial, jurisdictional, and community),” that make some area lakes’ homeowners reluctant “to abandon their use of aging and failing septic waste systems and connect to community sewer systems, or other engineered alternatives.”
The study would focus on Flathead, Whitefish and Echo Lakes, with the goal of informing solutions statewide.
“It’s a complex issue,” Koopal said, “and what we’ve found here locally is that, to our best efforts, we’ve failed to move this forward, and so we’re looking at state leadership on the topic to provide a road map and template that will better describe the funding opportunities and also educate the public on the issue and help local governments navigate this complex topic.”
The Flathead Basin Commission voted to forward its proposal to the Legislature’s Water Policy Interim Committee, which next meets Monday and Tuesday and will develop legislation for next year’s session. “Ideally, the study bill would come before the 2019 Legislature,” Lieser said.
If that happens, and a bill passes, Lieser’s hopeful that the Legislative Services Division’s study can guide the following session so that “we could get some kind of legislation that would possibly require inspection of septic systems, possibly support more intensive monitoring.”
But that would have to wait until the 2021 session. “It’s a long road for sure,” Lieser acknowledged.
Lieser has already learned this issue's challenges. During his time in the Legislature, he introduced a resolution requesting a study of ways to inspect and regulate septic systems. It died before coming to a vote.
But that hasn’t deterred water-watchers from bringing the issue back to Helena. The region’s popularity is only growing, and the trickles of waste running toward the lakes, Bansak said, are just one symptom of a much bigger challenge.